docs: def get_item(self, key):
          """
          Return the tus url of a file, identified by the key specified.
  
          :Args:
              - key[str]: The unique id for the stored item (in this case, url)
          :Returns: url[str]
          """
          result = self._db.search(self._urls.key == key)
          return result[0].get('url') if result else None